From 68582dd868032944a794f4eb7bfa2e71d29891f5 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Wed, 13 Nov 2024 00:59:53 +0000
Subject: [PATCH] add parallel query for current membership state

Signed-off-by: Jason Volk <jason@zemos.net>
---
 src/service/rooms/state_cache/mod.rs | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/service/rooms/state_cache/mod.rs b/src/service/rooms/state_cache/mod.rs
index 11684eab..6e330fdc 100644
--- a/src/service/rooms/state_cache/mod.rs
+++ b/src/service/rooms/state_cache/mod.rs
@@ -10,7 +10,7 @@ use conduit::{
 	warn, Result,
 };
 use database::{serialize_to_vec, Deserialized, Ignore, Interfix, Json, Map};
-use futures::{stream::iter, Stream, StreamExt};
+use futures::{future::join4, stream::iter, Stream, StreamExt};
 use itertools::Itertools;
 use ruma::{
 	events::{
@@ -566,6 +566,24 @@ impl Service {
 		self.db.userroomid_leftstate.qry(&key).await.is_ok()
 	}
 
+	pub async fn user_membership(&self, user_id: &UserId, room_id: &RoomId) -> Option<MembershipState> {
+		let states = join4(
+			self.is_joined(user_id, room_id),
+			self.is_left(user_id, room_id),
+			self.is_invited(user_id, room_id),
+			self.once_joined(user_id, room_id),
+		)
+		.await;
+
+		match states {
+			(true, ..) => Some(MembershipState::Join),
+			(_, true, ..) => Some(MembershipState::Leave),
+			(_, _, true, ..) => Some(MembershipState::Invite),
+			(false, false, false, true) => Some(MembershipState::Ban),
+			_ => None,
+		}
+	}
+
 	#[tracing::instrument(skip(self), level = "debug")]
 	pub fn servers_invite_via<'a>(&'a self, room_id: &'a RoomId) -> impl Stream<Item = &ServerName> + Send + 'a {
 		type KeyVal<'a> = (Ignore, Vec<&'a ServerName>);